Katana Explained: An Exploration into the Heart of Japanese Swords

The katana, a curved, single-edged sword, is the weapon most associated with the samurai warriors of feudal Japan. However, it transcends its role as a mere weapon, as it evolved as a status symbol and work of art. Today, it remains one of the most iconic and revered weapons in Japanese history and culture.

This article discusses the unique characteristics of a katana, its metallurgy, its history, and how it became the symbol of samurai warriors.

What Exactly Is a Katana?

The term katana is often used to refer to Japanese swords in general, but in sword terminology, it specifically refers to a long sword with a blade length of over 60 centimeters long. Worn with its cutting edge up and tucked into the belt, the katana served as the weapon and badge of the samurai as none other than the samurais were permitted to wear the long sword.

Designed for powerful slashing attacks, the katana’s edge faces upwards, allowing both actions of drawing and cutting to be executed at the same time. It replaced the earlier tachi sword, which was worn slung from a belt with the cutting edge facing down, requiring two motions to wield the sword.

Characteristics of the Katana Sword

Apart from its cultural and historical significance, the katana is valued for its exceptional craftsmanship and aesthetic qualities.

Here are the unique characteristics of the samurai sword:

Blade

Japanese swords are most known for their curved blades, which also have several aesthetic features that make them a work of art. Katana blades feature the visible pattern along the cutting edge (hamon) and a distinctive blade surface.

Curvature or Sori

The katana blade has a shallow curvature that may be at the center, near the tip, or toward the hilt. Experts determine the sword blade curvature by measuring the distance from the back of the blade to an imaginary straight line, drawn from the tip to the hilt, excluding the tang.

Temperline Pattern or Hamon

Katana blades feature a genuine hamon, formed by differential hardening treatments. There are various types of hamon patterns, ranging from straight to waves, arcs, clouds, and such. The hitatsura has a wild and rugged look, making it the most striking of all types.

Steel’s Surface or Jigane

The traditional katana blade is often darker than modern steel and is not reflective. When examining the surface, there’s a difference between the whitish steel color on the cutting edge and the grayish steel color on the other side.

Grain Patterns or Jihada

While forging the katana blade, the swordsmith repeatedly folded the steel, resulting in a distinct grain pattern called jihada. Depending on the technique, the grain patterns may feature straight lines, wavy lines, swirls, or a mix of linear and circular motifs.

Size and Length

Generally, Japanese blades are categorized based on their length. The blade length is measured from the base of the blade, excluding the tang, to the tip. A katana has a blade length of over 60 centimeters or 23 inches (over 2 shaku in Japanese).

Hilt or Tsuka

The hilt of a katana is called tsuka, consisting of the sword guard (tsuba) and other decorative metal fittings. It is usually covered with samegawa (shark skin), sometimes ray skin, and a braided hilt wrapping. The samurai often changed their sword mountings to flaunt their style and personality.

Sword Guard or Tsuba

The most functional accessory of the katana, the tsuba is the sword guard that protects the hand of swordsmen. Sword guards are usually disk-shaped, but others are rectangular with rounded corners. There is even a four-lobed shape called mokko.

The tsuba is functional and decorative, as some artisans even crafted elaborate designs that served as family heirlooms. Many tsuba artisans used gold and silver, as well as colored stones. The sukashi tsuba has a decorative cutout design, though it may not be suitable for battle.

Other Metal Fittings

Often with matching designs, the fuchi and kashira protect both ends of the hilt. The fuchi is the collar next to the sword guard, while the kashira is on the pommel. On the other hand, the menuki is the metal decoration placed under the hilt wrapping.

Scabbard or Saya

The katana comes in a scabbard or saya, often made of wood. To be placed in a saya, the sword has a collar called habaki, supporting the hilt. The katana is mounted in either shirasaya, a simple wooden scabbard, or koshirae, a lacquered scabbard with several metal ornaments. The samurai carried the katana through the obi sash. Sometimes, they fastened it to a sword carrier or koshiate attached to a belt.

What Defines an Authentic Katana?

An authentic katana is hand forged by a licensed Japanese swordsmith using traditional production methods and holds an artistic value. A traditionally-made katana, a nihonto, is made from tamahagane and has all the artistic features, such as the hamon, jigane, and jihada. It also comes with official paperwork called origami, stating its value and quality to confirm its authenticity.

Depending on the swordsmith and other factors, an authentic katana may cost around $7,500, but works of well-known master swordsmiths may even be around $50,000 or higher. On the other hand, high-quality replicas are about $1,000 or less. Depending on its quality, a katana replica can also be functional for tameshigiri or test-cutting practice.

Are Katana Swords Illegal in Japan?

Ordinary citizens can legally own a katana, but the sword must have cultural or historical significance. It has to be registered with the Nihon Token Hozon Kai and comes with a certificate of authenticity and permit, which has to stay with the sword at all times. The rule applies to antique and newly made katana swords by licensed swordsmiths.

However, decorative and training swords like iaito with zinc-aluminum blades that cannot be sharpened are exempted. In Japan, the katana is under the Firearm and Sword Possession Control Law, which forbids individuals from carrying the sword out in the open. One may get a permit to have a katana sword for home ownership, but it has to be kept in the house.

The Japanese government also allows licensed swordsmiths to produce a maximum of two long swords per month, and only traditionally made Japanese katana forged from tamahagane—can be licensed. On the other hand, unlicensed katana swords or ones crafted by unlicensed swordsmiths are confiscated and the owner charged with possession of illegal weapons.

The Katana Sword in Martial Arts

The katana is the best-known Japanese weapon with many using it in martial arts today. Here are the Japanese martial arts that utilize the katana—or other alternatives that replicate the qualities of the real sword.

In Kenjutsu

The katana is the defining blade of kenjutsu, which focuses on the traditional Japanese art of sword fighting. The samurai practiced the sword art since the 4th century CE, but it began to decline in the late 1860s due to the invention of firearms. Still, the Japanese military revived the interest in sword fighting skills, making it relevant to modern times.

Today, kenjutsu practitioners train with a wooden sword called bokken, roughly the same size and weight as the katana. The wooden sword allows the practitioners to practice sword fighting without the risk of injury or death.

In Kendo

The modern equivalent of kenjutsu, the kendo focuses on balance, speed, and fluidity in its techniques. Since the fighter’s goal is to end the combat as quickly as possible, training requires targeting areas such as the head, neck, forearms, and abdomen.

Instead of a real katana sword, kendo practitioners use the bamboo training sword shinai when training in pairs. The shinai, a bundle of bamboo strips bound together, is a safer alternative to the steel katana and wooden sword. Training in the kendo dojo uses the bokken.

In Iaido

The iaido involves perfecting the control of the katana sword. The sword art trained the warrior for a surprise attack so he could respond instantly. In the older iaido, practitioners would use wooden katana or bokuto. However, a practitioner would not benefit from the saya practice since a wooden sword has no scabbard.

Today, iaido practitioners use iaito or blunt katana blades in training but never in contact drills. Modern iaido is a non-competitive art, though some competitions require participants to perform sword movements in front of judges.

In Battōjutsu

Also referred to as iaijutsu, the battōjutsu focuses on quickly drawing the katana from the scabbard and warding off an attack. Unlike other martial arts, the movements in battōjutsu are smooth, controlled, yet instantaneous. Practitioners often start practicing with a mock sword with an aluminum alloy blade and later with the real katana sword.

In Toyama Ryu

The Toyama Ryu focuses on the practical application of the katana sword. It is a relatively modern sword art, but its principles draw from the philosophy and techniques of the samurai era. Today, it remains relevant for its alternative perspective to Japanese swordsmanship.

The Japanese Imperial Army created the sword art out of necessity because soldiers had to master swordsmanship quickly without years of study. After observing the European close-combat techniques in World War I, they adapted the moves for the katana on the battlefield.

Katana Sword Forging and Appreciation

Most swordsmiths in Japan craft the katana from tamahagane, high-quality steel made from the traditional tatara furnace. Some use sponge iron (kangan-testsu) or electrolytic iron (denkai-tetsu), though tamahagane is generally considered the best steel for sword making.

Japanese swordsmiths had mastered forging blades that were hard enough to retain a sharp cutting edge, but flexible at the same time to withstand heavy blows. They did this by incorporating a softer steel core into the harder steel forming the edge, and forged them together by heating, folding, hammering, and quenching.

The core steel of a katana blade (shingane) is covered by an outer steel jacket (kawagane). The shingane serves as a shock absorber, preventing the blade from breaking upon impact. However, there are various methods in creating a Japanese blade, and different swordsmiths may employ their own unique techniques.

History of the Katana Sword

The invention of the katana was a response to the changing nature of battles, demanding quicker response in combat. It also marked the transition of using the Japanese sword from fighting on horseback to fighting on foot. More than that, the katana represents the pinnacle of Japanese sword development, which began in ancient times.

In the Muromachi Period (1338–1573)

Within the Muromachi period emerged a century of military struggle known as the Sengoku period, the Age of the Country at War. During the tumultuous period, the uchigatana developed out of the need for speed in combat. The samurai wore their uchigatana edge-up in their belts, making it easier to draw and strike compared to the earlier slung tachi that required two actions to wield the sword.

At first, the uchigatana complemented the tachi, but it later became so popular that it replaced the tachi. Eventually, swordsmiths started to forge uchigatana in short and long lengths. The shorter blades were called wakizashi, while the longer blades were called katana. The wearing of paired swords, one long and one short among the samurai class also became common.

In the Momoyama Period (1574–1600)

During this period, sword mountings became very expensive and elaborate. Swordsmiths started incorporating precious metals, lacquer, and other materials to crafting tsuba, sword fittings, and other metal ornaments such as fuchi, kashira, and menuki. Some uchigatana remained simple and functional for combat, but those heavily decorated were commonly gifted to high-ranking samurai.

In the Edo Period (1603–1867)

During this period, the daisho, a sword set of katana and wakizashi, became the symbol of the samurai class. Still, merchants carried the short sword for self-defense when traveling. The design of the daisho also had regulations when worn for formal or ceremonial use. So, a wealthy samurai would have had several sword fittings for a single blade, choosing the most suitable for a given occasion.

In the Meiji Period (1868–1889)

In 1868, the Meiji Restoration led to the abolition of the feudal system, so the samurai also lost their privileged position. The emperor regained power and formed a national army, which conscripted men from society. In 1876, the Meiji government issued the Hatorei edict, which prohibited the carrying of swords in public. The government also began to modernize the Japanese military, so the katana swords were no longer practical for modern combat. 

Facts About the Japanese Katana

The katana served both as a weapon and the soul of the warrior. No samurai would ever be without his katana, so the sword would tell the world that its owner was a social and military elite. Here are the things you need to know about the samurai sword:

The samurai wore the daisho, a sword set of katana and wakizashi.

The term daisho translates as large and small, in reference to the longer sword katana and shorter sword wakizashi. It comes from the Japanese words daito or long sword and shoto or short sword. The shorter version of the katana, the wakizashi measures around 45 centimeters long. It served as a secondary weapon when katana was not allowed upon entering public buildings.

The meaning of long sword and short sword changed over centuries.

Today, swords of more than 2 shaku, approximately 60 centimeters, are called daito or long swords. On the other hand, swords shorter than 2 shaku but longer than 1 shaku, approximately 30 centimeters, are called shoto or short swords. Hence, the katana is considered a long sword and the wakizashi a short sword. Also, the tanto is a dagger with a maximum length of 1 shaku.

Swordsmen used wooden swords in training to preserve katana blades.

In the Muromachi period, martial arts training became common, so swordsmen wielded wooden swords called bokken to practice their sword fighting skills while preventing injury and preserving the katana blades. However, wooden swords also served as a weapon for actual combat. In the famous Japanese legend, Miyamoto Musashi defeated his opponent Sasaki Kojiro with a bokken.

The samurai followed a strict code of honor and discipline.

Carrying the katana and wearing the correct armor were vital aspects of being a samurai. But apart from military skills and fearlessness, the samurai followed a strict code of conduct known as bushido, emphasizing loyalty, honesty, and self-discipline. Today, bushido serves as the basic code of conduct for Japanese people.

The katana blade is longer than a ninjato or ninja sword.

The samurai sword had curved blades, but the ninja relied on straight, shorter blades. The ninjas were also more orthodox in using their swords. The ninjato handle was longer than the tsuka of a katana and had a stronger sword guard, which provided a step when climbing walls. As a multi-functional tool, ninja scabbards were also traditionally plain.

Conclusion

The samurai of feudal Japan trained in several weapons, especially the katana. Although many traditional arts associated with these warriors have disappeared, the art of Japanese sword making has persevered. Today, the katana remains significant not only in martial arts but also in Japanese culture and history.